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Biomedical subjects

B J Marais

Publications and source records attributed to B J Marais.

11 recordsLinked to original sources
PubMed2005

Diversity of disease in childhood pulmonary tuberculosis.

Many factors can influence the dynamic balance that exists between the host and the pathogen (M. tuberculosis), but the host immune response seems to be the most important. This is illustrated by the vulnerability of immune-compromised individuals to develop tuberculosis and by the age-related spectrum of disease witnessed in immune-competent children. This age-related spectrum of disease reflects the ontogeny of the host immune response towards M. tuberculosis. Renewing our focus on the ontogeny of the immune response in children might provide valuable insights to direct future research regarding tuberculosis prevention, vaccine development and treatment.

Aging↗
PubMed2005

The association of prolonged breastfeeding and allergic disease in poor urban children.

The fact that breastfeeding may protect against allergic disease remains controversial, with hardly any reports from developing countries. This study investigated the association between allergic disease in children and prolonged breastfeeding. Data were collected from a 15% random sample of households from two poor suburbs of Cape Town, South Africa. Parents completed a validated International Study on Asthma and Allergies in Childhood questionnaire on allergic diseases for children aged 6-14 yrs. Other questions included breastfeeding duration, maternal smoking and parental allergy. Results were adjusted for possible confounders and for possible clustering within the household. Out of the 861 children included in the study, allergic disease in general, and hay fever in particular, were significantly less frequent in those with prolonged (> or =6 months) breastfeeding. There was a significant linear inverse association between breastfeeding duration and allergic disease in children without allergic parents, but not in children with an allergic predisposition. In conclusion, these results from a developing country suggest a protective effect of prolonged breastfeeding on the development of allergic disease, particularly hay fever, in children born to nonallergic parents. This protective effect was not found in children with an allergic predisposition.

Adolescent↗
PubMed2004

Childhood turberculosis: reflections from the front line.

Tuberculosis is a major cause of childhood morbidity and mortality in high-burden settings, particularly in the third-world settings. Effective intervention in these resource-limited areas requires a clear focus on high-risk groups. Children rarely contribute to disease transmission, but their disease is the direct result of continued transmission within the community. The burden of childhood tuberculosis reflects the level of epidemiological control achieved within the adult population. Adequate diagnosis and treatment should be available for every child, but reducing the burden of childhood disease requires a concerted effort to contain the epidemic.

Antitubercular Agents↗
PubMed2004

The clinical epidemiology of childhood pulmonary tuberculosis: a critical review of literature from the pre-chemotherapy era.

The pre-chemotherapy literature represents an impressive body of evidence that clarifies important epidemiological concepts in childhood tuberculosis. Reports describe the major transitions in tuberculosis, from exposure to infection and from infection to disease (morbidity and mortality), without the influence of chemotherapy. Children with household exposure to a sputum smear-positive source case experienced the greatest risk of becoming infected and of developing subsequent disease. Household exposure to a sputum smear-negative source case or non-household exposure still posed an appreciable, although greatly reduced, risk. Infection in children less than 2 years of age indicated a probable household source case. The majority of older children who were infected did not have a household source identified, and presumably became infected in the community. The annual risk of infection (ARI) was not constant across all ages, but seemed to increase during periods of widening social contact. Infants and adolescents were the groups at highest risk for disease development and death following primary infection.

Adolescent↗
PubMed2004

The natural history of childhood intra-thoracic tuberculosis: a critical review of literature from the pre-chemotherapy era.

The pre-chemotherapy literature documented the natural history of tuberculosis in childhood. These disease descriptions remain invaluable for guiding public health policy and research, as the introduction of effective chemotherapy radically changed the history of disease. Specific high-risk groups were identified. Primary infection before 2 years of age frequently progressed to serious disease within the first 12 months without significant prior symptoms. Primary infection between 2 and 10 years of age rarely progressed to serious disease, and such progression was associated with significant clinical symptoms. In children aged >3 years the presence of symptoms represented a window of opportunity in which to establish a clinical diagnosis before serious disease progression. Primary infection after 10 years of age frequently progressed to adult-type disease. Early effective intervention in this group will reduce the burden of cavitating disease and associated disease transmission in the community. Although the pre-chemotherapy literature excluded the influence of human immune deficiency virus (HIV) infection, recent disease descriptions in HIV-infected children indicate that immune-compromised children behave in a similar fashion to immune immature children (less than 2 years of age). An important concept deduced from the natural history of tuberculosis in childhood is that of relevant disease. Deciding which children to treat may be extremely difficult in high-prevalence, low-resource settings. The concept of relevant disease provides guidance for more effective public health intervention.

Adolescent↗
PubMed2003

Danish bacille Calmette-Guérin vaccine-induced disease in human immunodeficiency virus-infected children.

An analysis of isolates of Mycobacterium tuberculosis complex was performed to determine the prevalence of bacille Calmette-Guérin (BCG) disease among human immunodeficiency virus (HIV)-infected children. Speciation was done with polymerase chain reaction; 183 isolates from mycobacterial cultures for 49 HIV-infected patients were analyzed. The Danish Mycobacterium bovis BCG strain was isolated from 5 patients. No cases of Tokyo M. bovis BCG strain disease were detected. All patients were asymptomatic at birth, <12 months of age, and severely immunodeficient at presentation. Four patients had regional axillary adenitis ipsilateral to the vaccination site, and 2 had pulmonary BCG disease. Two patients with regional BCG disease had simultaneous pulmonary M. tuberculosis infection. Although chest radiographic features were similar to those seen in patients with tuberculosis, BCG disease should be considered in HIV-infected infants with right axillary adenitis ipsilateral to the vaccination site. Young, symptomatic, HIV-infected infants are at risk for BCG-related complications. Controlled, population-based studies are needed to assess the risk of BCG in HIV-infected children.

AIDS-Related Opportunistic Infections↗
PubMed2003

A child with neurobrucellosis.

An 11-year-old boy presented with chronic meningitis followed by acute flaccid paralysis. The aetiology remained uncertain until the brucellar serology test became positive and there was a good response to specific antimicrobial therapy. Nerve conduction studies confirmed a proximal radiculopathy. Awareness of the condition and performance of the appropriate tests will differentiate neurobrucellosis from other chronic central nervous system infections.

Anti-Bacterial Agents↗